1. Field of the Invention
The present invention relates to a recording apparatus that forms an image on a recording sheet on the basis of image information.
2. Description of the Related Art
A recording apparatus is used as an output device for a computer or an output device for a digital image. In addition, a recording apparatus is also used for a photocopier, a scanner, a complex machine of these, or a system. The recording apparatuses can be classified according to recording method into categories, for example, a thermal transfer type, an ink jet type, a laser beam type, and a wire dot type. In addition, the recording apparatuses can also be classified into either a serial type or a line type. The serial type uses both the main scanning by a recording head and the sub-scanning by paper feeding. The line type uses a line recording head and performs recording using only the sub-scanning. In a thermal transfer recording apparatus, an ink sheet is pressed against a recording sheet and heated so as to transfer ink, and image recording is thereby performed. Particularly in a line type thermal transfer recording apparatus, a plurality of heating elements arranged in the width direction of a recording sheet are selectively driven, the recording sheet and an ink sheet are conveyed in the sub-scanning direction, and dot-line-like images are thereby sequentially recorded.
Recently, with the advancement of image input devices such as a digital camera, a digital camcorder, and a scanner, a thermal transfer recording apparatus has gotten a lot of attention. A thermal transfer recording apparatus is a recording apparatus suitable for printing out electronic image information picked up with a still camera or a camcorder, through a computer or a memory medium. In other types of recording apparatuses such as an ink jet recording apparatus, there is only a binary choice between to form a dot or not. Therefore, small dots are formed on a recording sheet and for example, error diffusion is used so as to obtain apparent resolution and gradation.
In contrast, in the case of a thermal transfer recording apparatus, the value of heat that can control a pixel can be easily changed. Therefore, a pixel can have a wide range of gradation. Therefore, compared to other recording apparatuses such as an ink jet recording apparatus, a thermal transfer recording apparatus has the advantage that a smooth and high-quality image can be obtained. In addition, in a thermal transfer recording apparatus, since the performance of a thermal head as a recording unit and the performance of recording sheet material have been improved, a print image even equal to a silver salt photograph in quality can be obtained. In step with the recent advancement of digital cameras, a thermal transfer recording apparatus has gotten a lot of attention, particularly as a recording apparatus for a natural image.
In addition, there has arrived a system such that a thermal transfer recording apparatus is directly connected to an image pickup device, such as a digital camera or a digital camcorder, with a cable, and performs printing out without using a device that processes image information, such as a computer. Moreover, there has arrived a system such that an image pickup device, such as a digital camera or a digital camcorder, with integral thermal transfer recording apparatus, directly prints out the photographed information without using a device that processes image information, such as a computer. These systems make it possible to print out the image information from a digital camera or a digital camcorder, easily and photographically. Therefore, a thermal transfer recording apparatus has increasingly gotten a lot of attention. However, in a thermal transfer recording apparatus, in order to perform full color printing, it is necessary to transfer a plurality of colors of inks, repeatedly and one over the other. A general configuration to realize this will hereinafter be described.
FIGS. 4A and 4B are sectional views of a first example of a conventional thermal transfer recording apparatus. FIG. 4A shows a state in which recording is being performed on a recording sheet P. FIG. 4B shows a state in which the recording sheet P has been moved to the starting position for recording in the next color. In FIGS. 4A and 4B, recording sheets P are contained in a cassette 101. Only the top sheet is separated and fed by a paper feeding roller 102 and a separating unit 103. The recording sheet P is conveyed to the nip between a recording head (thermal head) 104 and a platen roller 105. The circumference of the platen roller 105 is slightly longer than the full length of the recording sheet P. The recording sheet P is wound around the platen roller 105. As shown in FIG. 4A, an ink sheet 106 pulled out from a cartridge 110 and the wound recording sheet P are pressed against each other by the recording head 104 and the platen roller 105. The recording head 104 generates heat to transfer the ink on the ink sheet 106 onto the recording sheet P, and the platen roller 105 is rotated, thereby performing image recording (printing).
After the printing in a first color is completed in the state shown in FIG. 4A, the recording head 104 releases the ink sheet 106 from the recording sheet P. The platen roller 105 is then further rotated so as to locate the recording sheet P at the print starting position shown in FIG. 4B. Next, printing in a second color is performed in the same manner as the first color. If necessary, printing is repeatedly performed in third, fourth . . . colors in the same manner. In this way, by printing in three colors: yellow, magenta, and cyan, a full color printing can be performed.
FIGS. 5A and 5B are sectional views of a second example of a conventional thermal transfer recording apparatus. FIG. 5A shows a state in which recording is being performed on a recording sheet P. FIG. 5B shows a state in which the recording sheet P is being moved to the starting position for recording in the next color. In FIGS. 5A and 5B, recording sheets P are contained in a cassette 201. Only the top sheet is separated and fed by a paper feeding roller 202 and a separating unit 203. The recording sheet P is conveyed to the nip between a recording head (thermal head) 204 and a platen roller 205. As shown in FIG. 5A, an ink sheet 206 pulled out from the cartridge 210 and the conveyed recording sheet P are pressed against each other by the recording head 204 and the platen roller 205. The recording head 204 generates heat to transfer the ink on the ink sheet 206 onto the recording sheet P, thereby performing image recording (printing). A pair of rollers consisting of a capstan roller 209 and a pinch roller 208 is disposed on the downstream side of the recording (transferring) section. When the recording operation is performed, the recording sheet P is conveyed by these rollers.
After the printing in a first color is completed in the state shown in FIG. 5A, the recording head 204 releases the ink sheet 206 from the recording sheet P. As shown in FIG. 5B, the capstan roller 209 and the pinch roller 208 are rotated in the opposite direction from that during the printing operation so as to return the recording sheet P to the starting position. Next, printing in a second color is performed in the same manner as the first color. If necessary, printing is repeatedly performed in third, fourth . . . colors in the same manner. In this way, by printing in three colors: yellow, magenta, and cyan, a full color printing can be performed.
The recording sheets P in the cassette 101 and the ink sheet 106 in the cartridge 110 in FIGS. 4A and 4B, and the recording sheets P in the cassette 201 and the ink sheet 206 in the cartridge 210 in FIGS. 5A and 5B are consumables and need to be replaced or supplied. In general, the ink sheet 106 or 206 is supplied to users in the form of a cartridge 110 or 210 such that both ends of the ink sheet are wound on two bobbins, and the two bobbins and the ink sheet are contained in a frame 107 or 207. In FIGS. 4A, 4B, 5A, and 5B, the frames 107 and 207 are frames of the cartridges 110 and 210, respectively.
The frames 107 and 207 of the cartridges 110 and 210 have recesses 110a and 210a, respectively. When the cartridge 110 or 210 is attached to a recording apparatus, as shown, the recording head (thermal head) 104 or 204 in the apparatus body is located in the recess 110a or 210a. At this time, the cartridge is guided by the recording head to a predetermined position.
The first example of FIGS. 4A and 4B has the following disadvantages. Since a platen roller having a circumference slightly longer than the full length of the recording sheet P is necessary, the size of the apparatus is increased. In addition, since a mechanism that winds and holds the recording sheet P around the platen roller is necessary, the apparatus is complicated. However, the first example has the following advantage. The starting position of printing in the second color is just behind the ending position of printing in the first color. Therefore, the recording sheet P need not be returned as in the second example of FIGS. 5A and 5B. Therefore, the speed of recording operation is high. On the other hand, the second example of FIGS. 5A and 5B has the disadvantage that it takes a long time to print, but has the advantage that the apparatus is compact and simple.
In a thermal transfer recording apparatus, in order to obtain high quality print, it is necessary to use special paper having a surface onto which ink is easily transferred. Therefore, for example, a cartridge containing an ink sheet for printing 50 recording sheets, and 50 recording sheets are sold by the set. When a user uses the recording sheets and the cartridge sold by the set, first, the user unpacks them, then attaches the cartridge in the apparatus body, and places the recording sheets in the cassette. It is troublesome to place the recording sheets and the cartridge in different places.
FIGS. 6A and 6B each schematically show an example of a set with a cartridge and recording sheets. FIG. 6A shows an A6 size recording sheet and an ink cartridge for A6 size. FIG. 6B shows an A7 size recording sheet and an ink cartridge for A7 size. In the case of a thermal transfer recording apparatus, in order to reduce the waste of the ink sheet, it is necessary to prepare different ink sheets according to the size of recording sheet. Therefore, as shown in FIGS. 6A and 6B, for example, A6 size recording sheets and a cartridge containing an ink sheet for A6 size recording sheets are sold by the set, and A7 size recording sheets and a cartridge containing an ink sheet for A7 size recording sheets are sold by the set. Users buy the sets according to their purposes. When the printing of A7 size recording sheets is performed after the printing of A6 size recording sheets is performed, a user needs to take out the A6 size recording sheets and the cartridge for A6 size recording sheets and then, instead of them, to load the A7 size recording sheets and the cartridge for A7 size recording sheets.
The unloaded A6 size recording sheets and cartridge for A6 size recording sheets need to be kept for future use. However, the cartridge and the recording sheets are separated. In addition, since the cartridge and the recording sheets must not be subjected to dust and direct sunlight, they need to be kept in, for example, bags. Therefore, it is troublesome to handling them. To eliminate such troublesomeness, an integrated cartridge containing both an ink sheet and recording sheets is proposed in Japanese Patent No. 2523355 and Japanese Patent Laid-Open No. 2000-108442 (corresponding to U.S. Pat. No. 6,069,642).
In the transfer paper cartridge disclosed in Japanese Patent No. 2523355, an ink sheet container and a recording sheet container are integrated. However, printing cannot be performed with the ink sheet contained in the cartridge. Therefore, when printing is performed, it is necessary to take out the ink sheet from the cartridge and to load the ink sheet to the printing position. The mechanism therefore complicates the apparatus, and it is difficult to maintain reliability.
The Japanese Patent Laid-Open No. 2000-108442 solves the problem of Japanese Patent No. 2523355 and discloses an integrated cartridge (integrated cassette) such that it is not necessary to load an ink sheet to the printing position after the cartridge is loaded in an apparatus, and printing can be performed with the ink sheet contained in the cartridge. The configuration of Japanese Patent Laid-Open No. 2000-108442 can eliminate the trouble to separately place an ink sheet and recording sheets. In addition, the configuration of Japanese Patent Laid-Open No. 2000-108442 can provide a highly usable printer such that when different types of recording sheets are used, there is no trouble to separately keep the unloaded ink sheet and recording sheets.
However, the recording apparatuses of Japanese Patent No. 2523355 and Japanese Patent Laid-Open No. 2000-108442 have problems to be solved in terms of the installation area and the height of the apparatus. FIGS. 7A, 7B, 8A, and 8B are plan views and longitudinal sectional views showing the definitions of the installation area and the height of the recording apparatus. FIGS. 7A and 7B show a recording apparatus configured to convey recording sheets contained in an integrated cartridge attached to an apparatus body, in their longitudinal direction (in a direction parallel to the long side). FIG. 7A is a plan view. FIG. 7B is a sectional view taken along line VIIB-VIIB of FIG. 7A. In FIGS. 7A and 7B, a cartridge having a recording sheet container 2 and an ink sheet container 3 is attached to a cartridge mounting portion of a frame 1 of a recording apparatus. In addition, FIGS. 7A and 7B show recording sheets loaded in the cartridge (recording sheet container 2) and a recording sheet sent out from the cartridge for printing. The installation area 6 of the recording apparatus is the projected area of the recording apparatus body onto a plane parallel to the recording sheets 5. The height 9 of the recording apparatus is the size of the recording apparatus body in the direction perpendicular to a plane parallel to the recording sheets 5.
However, the conventional recording apparatuses have problems to be solved when they are designed such that the installation area is minimized. The problems will be described with reference to FIGS. 7A and 7B. In FIG. 7A, reference letter D denotes the longitudinal direction of the recording sheets 5a contained in the integrated cartridge 10 attached to the body, and reference letter E denotes the longitudinal direction of the recording sheet 5b being subjected to recording in the image transferring section 20. The recording apparatus is configured such that the longitudinal direction D is parallel to the longitudinal direction E. The longitudinal direction of the recording sheet discharged after the recording is also the same as (parallel to) the direction E during the recording. Such configuration is inevitable because the printing operation is performed by straight conveying one of the recording sheets contained in the cartridge 10 with a roller to the image transferring section 20.
In FIG. 7A, the area surrounded by the dashed line 6 designates the installation area of the recording apparatus. In this installation area and on both sides of the integrated cartridge 10, areas 16 are provided. These areas 16 are used for disposing “parts that cannot be disposed in an area Z through which a recording sheet passes during the printing, in terms of design” or “parts that can be but should not be disposed in the area Z.” The “parts that cannot be disposed in terms of design” include mechanical parts such as a gear driving a roller and stationary parts such as a shaft bearing. Since these parts transmit driving force to conveyance rollers so as not to interfere with the recording sheet being conveyed, these parts cannot be disposed in the area Z through which a recording sheet passes.
The “parts that should not be disposed” include electrical parts such as a motor, a power source board, and a control board. These parts include many large parts such as a motor case and an electrolytic capacitor. If these parts are disposed in the area Z through which a recording sheet passes, the height of the apparatus body increases. Therefore, these parts should not be disposed in the area Z. In addition, lines that must not be subjected to electrical noise, for example, signal lines to the recording head, should be as short as possible to ensure stable operation. Therefore, lines of, for example, a control board are generally disposed on both sides of the board to minimize their length. For these reasons, spaces (areas) 16 for disposing the above-described parts are provided on both sides of the integrated cartridge 10.
The installation area 6 of the recording apparatus is the sum of the areas of the recording sheet container 2 and the spaces 16. The size of the apparatus body increases with an increase in the size of the recording sheet. This is the same regardless of the direction of the recording sheet. FIGS. 8A and 8B show a recording apparatus configured to convey recording sheets contained in an integrated cartridge attached to an apparatus body, in their width direction (in a direction parallel to the short side). FIG. 8A is a plan view. FIG. 8B is a sectional view taken along line VIIIB-VIIIB of FIG. 8A. That is to say, FIGS. 8A and 8B show a recording apparatus in which recording sheets are conveyed in the portrait position in contrast to the landscape position in the recording apparatus of FIGS. 7A and 7B. In FIGS. 8A and 8B, the same reference numerals are used to designate the components corresponding to those in FIGS. 7A and 7B. As is clear from FIGS. 7A, 7B, 8A, and 8B, the installation area 6 of the recording apparatus is the sum of the areas of the recording sheet container 2 and the spaces 16. Therefore, regardless of whether the recording sheets are in the landscape position or the portrait position when they are subjected to printing and are in the container, the installation area 6 of the recording apparatus cannot be reduced.
For the conventional recording apparatus that uses an integrated cartridge, the installation area of the apparatus depends largely on the size of the recording sheet. In addition, spaces for disposing “parts that cannot be disposed in an area Z through which a recording sheet passes during the printing, in terms of design” or “parts that can be but should not be disposed in the area Z” are necessary. Therefore, although the conventional recording apparatuses shown in FIGS. 7A, 7B, 8A, and 8B can provide high usability by using an integrated cartridge, it is very difficult to reduce the installation area 6 of the recording apparatus, and reduction in size and weight is limited.